肺错构瘤薄层重组CT表现与误诊分析

Thin Layer Reconstruction CT Manifestations and Misdiagnosis Analysis of Pulmonary Hamartoma

目的分析肺错构瘤的薄层重组CT表现及误诊原因。方法回顾性分析经手术病理证实的肺错构瘤42例影像资料,观察肺错构瘤的薄层重组CT表现,分析误诊原因。结果 42例肺错构瘤均为周围型,单发。左肺24例（57.1%）。直径〈3 cm 39例（92.9%）。病灶边缘出现分叶32例（76.2%）,其中浅分叶27例,深分叶5例。所有病灶均边缘光滑,未出现毛刺。病灶邻近＂胸膜凹陷征＂出现5例（11.9%）。病灶内密度不均32例（76.2%）,其中钙化15例,可疑脂肪密度25例（其中可疑裂隙样或小点样可疑脂肪密度（19例）。＂血管穿过征＂23例（54.8%）,＂血管绕行征＂7例（30.4%）。所有病灶均轻度强化。误诊为肺癌12例,转移瘤4例,结核球2例,硬化性血管瘤7例,炎性肉芽肿1例。误诊率为61.9%（26例）。结论对可疑脂肪密度及＂血管穿过征＂认识不足是主要误诊原因。

Objective To analyse thin layer reconstruction CT performance and misdiagnosis causes of pulmonary hamartoma. Methods Imaging findings of 42 cases of pulmonary hamartoma confirmed by pathology were retrospectively analyzed. To observe the CT findings of pulmonary hamartoma by thin layer reconstruction,and analyze the causes of misdiagnosis. Results 42 cases of pulmonary hamartoma were peripheral type,single. Left lung in 24 cases（ 57. 1%）. 39 cases（ 92. 9%） were less than 3 cm in diameter. Lobulated sign were found in 32 cases（ 76. 2%）,in which 27 cases were shallow lobular,and 5 cases were deep lobular. All lesions were smooth on the edge,without burr. Pleural indentation were found in 5 cases（ 11. 9%）. 32 cases（ 76. 2%） were found uneven density,including 15 cases of calcification and 25 cases with fat density（ fat density couldn’t be measured in 19 cases which showed suspected crack like or dot like fat density）. Vascular cross sign were showed in 23 cases（ 54. 8%）,marginal blood vessel sign in 7 cases（ 30. 4%）. All lesions showed slight enhancement. Misdiagnosed as lung cancer in 12 cases,metastatic tumor in 4 cases,tuberculoma in 2 cases,sclerosing hemangioma in 7 cases,inflammatory granuloma in 1 cases. 26 cases（ 61. 9%） were misdiagnosed preoperative. Conclusion The main causes of misdiagnosis are the lack of understanding of the suspicious fat density and the vascular cross sign.